Doctors do not yet have drugs to cure diseases caused by [all] viruses. But they can give you shots to prevent some of these diseases.
from Germs Make Me Sick
written by Melvin Berger
illustrated by Marilyn Hafner
Harper, 2015 (revised edition)
EPUB edition, 2020
Here’s a definition to start us off this morning. “A vaccine is a substance that helps protect against certain diseases. Vaccines contain a dead or weakened version of a microbe. It helps your immune system recognize and destroy the living microbe during a future infection.” https://www.webmd.com/cold-and-flu/qa/what-is-the-definition-of-vaccine
Polio, short for poliomyelitis, is an infectious disease caused by the poliovirus. When I was growing up, polio was still a common and dreaded disease. It did not kill most of its victims, but many were forced to live with crippling aftereffects. There was no cure.
Franklin D. Roosevelt contracted polio in 1921. It left both his legs paralyzed. Shortly into his second term as president, he helped create what would become the March of Dimes Foundation, originally formed to to find a cure for polio.
The March of Dimes was Jonas Salk’s primary funding source as he researched his vaccine to prevent polio. Salk developed a “killed-virus” vaccine. He grew samples of the virus, then killed them with formaldehyde so they could not reproduce. The inactive strains of the virus tricked the immune system into producing protective antibodies to prevent an infection.
Most scientists, including Albert Sabin, believed only a live, but weakened microbe would be effective. They called Salk’s “killed-virus” vaccine dangerous. But it takes a long time to develop a live-virus vaccine. Funding went to Salk.
Between April 26, 1954 and the end of June that same year, 1.8 million people became “polio pioneers,” volunteering to participate in a double-blind experiment to prove the Salk vaccine’s efficacy. It was declared declared “safe, effective and potent,” on April 12, 1955.
Sabin’s oral vaccine did not become available until 1962. It was given on a sugar cube and quickly replaced Salk’s injection. The Sabin vaccine was less expensive and easier to administer. But according to the World Health Organization (WHO), although polio vaccination prevents countless infections, in 2019, Sabin’s live-virus vaccine was responsible for nine new polio cases. WHO calls it the final obstacle to eliminating polio and urges the use only of Salk’s killed-virus vaccine.
I was around ten years old when, after dinner one evening, Mom and Dad rounded us up and hiked with Gram the quarter mile to our elementary school. We were off to get our vaccination for polio.
It seemed like the whole neighborhood turned up. We chatted as we stood in line, waiting our turn. The proper amount of drops of the Sabin oral vaccine was dosed on a sugar cube and given to men, women, children, grandparents, and babies. It was easy.
According the CDC (Centers for Disease Control and Prevention), the United States has been polio-free since 1979.
The first step to developing a vaccine these days, is to discover the genetic code of the virus. This structure is used as a guide to learn which antibodies will create immunity in humans. Scientists then determine whether any of several vaccine candidates fight the virus effectively.
An antibody is the only component of our immune response that recognizes a virus before it has infected a cell. So right now, the only people who can produce antibodies against the protein in the COVID-19 virus are people who have recovered from an infection.
Two processes need to work together. It's the combination of antibodies to prevent further infection with the antibodies’ effect on a person’s own T-cells to clear out the existing infection, that will prove most effective.
Once an antibody is isolated, it must be tried out in people to see if it is effective (that’s the T-cell component) and what, if any, side-effects it might cause. This is necessarily a slow process. The collection of antibodies, the trials in real, infected people, and analysis of the data all take time. No one wants a drug that is ineffective. For sure no one wants one that is harmful.
Once a vaccine has gone through the clinical trials and determined to be safe and effective, scientists determine the proper dose. Making proper dosage adjustments could take a year or more. And we're not quite there, yet.
Scientists all over the world are looking for an effective and safe vaccine for COVID-19, delivered at the proper dose. When it is discovered, people all over the world will be very grateful., indeed.
-—stay curious! (and patient)